Wilfred Trotter is probably best known these days for two reasons. First, there is the wonderful mnemonic effect of his name. Who could ever forget, having once learned it, that "Trotter" was the man who popularized the concept of the "herd instinct" as a force in social life—especially when his surname evokes so well the gregarious quadrupeds to which he likens human society.
Second, Trotter's chief work, Instincts of the Herd in Peace and War, is often recalled as one of a number of works from the same era (the late 19th and early 20th centuries) dealing with the psychology of human groups, often from a critical perspective. Along with with the works of Le Bon, Bernays, etc., Trotter is therefore sometimes seen as antidemocratic—and is even accused of paving the way, like these other writers, for the propaganda techniques of fascist dictators and their counter-parliamentary putsches for unilateral power.